ID | Technique | Tactic |
---|---|---|
T1021.006 | Windows Remote Management | Lateral Movement |
T1021 | Remote Services | Lateral Movement |
Detection: Powershell Remote Services Add TrustedHost
Description
The following analytic detects the execution of a PowerShell script that modifies the 'TrustedHosts' configuration via EventCode 4104. It leverages PowerShell Script Block Logging to identify commands targeting WSMan settings, specifically those altering or concatenating trusted hosts. This activity is significant as it can indicate attempts to manipulate remote connection settings, potentially allowing unauthorized remote access. If confirmed malicious, this could enable attackers to establish persistent remote connections, bypass security protocols, and gain unauthorized access to sensitive systems and data.
Search
1`powershell` EventCode=4104 ScriptBlockText = "*WSMan:\\localhost\\Client\\TrustedHosts*" ScriptBlockText IN ("* -Value *", "* -Concatenate *")
2| rename Computer as dest, UserID as user
3| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText dest user
4| `security_content_ctime(firstTime)`
5| `security_content_ctime(lastTime)`
6| `powershell_remote_services_add_trustedhost_filter`
Data Source
Name | Platform | Sourcetype | Source |
---|---|---|---|
Powershell Script Block Logging 4104 | Windows | 'xmlwineventlog' |
'XmlWinEventLog:Microsoft-Windows-PowerShell/Operational' |
Macros Used
Name | Value |
---|---|
powershell | (source=WinEventLog:Microsoft-Windows-PowerShell/Operational OR source="XmlWinEventLog:Microsoft-Windows-PowerShell/Operational") |
powershell_remote_services_add_trustedhost_filter | search * |
powershell_remote_services_add_trustedhost_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
Setting | Value |
---|---|
Disabled | true |
Cron Schedule | 0 * * * * |
Earliest Time | -70m@m |
Latest Time | -10m@m |
Schedule Window | auto |
Creates Notable | Yes |
Rule Title | %name% |
Rule Description | %description% |
Notable Event Fields | user, dest |
Creates Risk Event | True |
Implementation
To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.
Known False Positives
user and network administrator may used this function to add trusted host.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
a powershell script adding a remote trustedhost on $dest$ . | 64 | 80 | 80 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | XmlWinEventLog:Microsoft-Windows-PowerShell/Operational |
XmlWinEventLog |
Integration | ✅ Passing | Dataset | XmlWinEventLog:Microsoft-Windows-PowerShell/Operational |
XmlWinEventLog |
Replay any dataset to Splunk Enterprise by using our replay.py
tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
Source: GitHub | Version: 3